There is plenty of environmental progress to keep us hopeful, in the daunting task of stewardship of the planet.

Earth Day began in 1970, at a time when the US was ushering in the Clean Air Act and the Clean Water Act and there was broad consensus on the need for environmental action. Nearly 50 years later, problems like rising global temperatures, melting Arctic sea ice, and the demographics putting pressure on food production and resources like forests, can make you want to scream or bury your head in the sand. But there is hope! People are mobilizing and technological innovation promises a host of solutions.

Here are 10 things to celebrate this Earth Day:

1. Solar energy has become the fastest growing and cheapest source of electricity worldwide. It is powering the rural homes of the poorest in Bangladesh, and whole countries like Portugal, which produced an amount of renewable energy equivalent to 103.6 per cent of the country's total mainland electric energy demand in the month of March.

2. Analysts are betting on big improvements in battery storage technology. Although it isn't clear when the tipping point will come, battery storage could ensure a continuous supply of energy through the grid even when sources fluctuate, as in the case of solar power. Advances in battery storage would also accelerate the move to electric vehicles, with huge repercussions for our transportation systems.

3. Cities, including many in the US, are taking the lead on reaching the targets outlined in the Paris climate agreement. The C40 Cities Climate Leadership Group, bringing together more than 90 cities representing over 650 million people and a quarter of the global economy, has several initiatives underway. One group of 13 leading mayors recently pledged to "transition to Fossil-Fuel-Free Streets by:

1) procuring, with our partners, only zero-emission buses from 2025; and

2) ensuring a major area of our city is zero emission by 2030."

4. China is stepping up with measures for better stewardship of the planet. Although its strong economic growth means overall emissions are still increasing, China has reached its 2020 "carbon intensity" targets ahead of time by implementing serious environmental policies and technological innovation.

5. "Circular economy" concepts are taking hold. Instead of continuing to mine resources, fashion them into products, use the products and then throw them away (the "take-make-waste" model), individuals, companies and policy makers are increasingly looking to a less wasteful "make-use-return" model of doing business. Apple has unveiled a disassembly robot named Daisy that can take apart up to 200 old iPhones per hour, recovering valuable materials for reuse. Disassembling 100,000 devices, Daisy can recover a host of materials, including 11 kilograms of rare earths, 770 kilograms of cobalt, and 1900 kilograms of aluminum.

6. More companies are making commitments to stop deforestation, and broad coalitions of stakeholders are tackling the problem. Satellite technology can help identify deforestation hotspots and track solutions. Here's just one example of corporate action : Taylor Guitars, a leading manufacturer of acoustic guitars, has projects in Cameroon and Hawaii to replant ebony trees and acacia koa trees. Guitar fingerboards and bridges are made from ebony wood, and koa wood is used for guitar backs, sides and tops, and these types of trees are being depleted. The company has launched long-term reforestation projects that won't pay off for decades, but could be crucial to the music of future generations. Founder Bob Taylor was quoted in his company's magazine as saying "Today Taylor Guitars buys mahogany from Fiji that some long-dead British guy planted 80 years ago. I want to be a long-dead American guy who planted trees that someone will make guitars from in the future."

7. Water conservation efforts are producing results. According to the US Geological Survey, US household water consumption is declining to mid-1990s levels. Efforts go beyond turning off the water while brushing teeth, and include regulatory changes and innovations in plumbing and infrastructure.

8. Packaging materials are improving. Dell and Ikea use "mushroom packaging" grown from agricultural waste products. Biodegradable and compostable bags are beginning to be introduced as substitutes for plastic bags. Organic and reusable food packaging solutions are appearing, and this year a Dutch supermarket introduced a plastic-free aisle.

9. More people, companies and organizations are calling for a carbon price or a carbon tax to introduce greater environmental accountability. The reasoning goes: why should limited natural resources be used for free, and why should polluting shared air and water not come with a price tag? Carbon trading markets exist, as well as offsets that are easy to purchase (for example, some airlines ask if you'd like to buy carbon offsets together with your ticket).

10. Individuals are stepping up with a multitude of small actions and solutions, starting with turning off the lights. Everyone must play their part. Richard Branson believes in a democratic process to solve global warming challenges, not just one or a few superhero solutions. For inspiration, check out Drawdown, the book, project and website launched by Paul Hawken. Hawken's researchers collected data, information and practical stories, creating what is something of an encyclopedia of solutions for climate change. And it is a work in progress, designed to be built on, with new solutions introduced as they are discovered.

Earth Day is also an opportunity to appreciate the beautiful, generous planet we all share, and to revel in its resilience and ours. Get outside this Earth Day, breathe the air, feel your feet on the ground, and be grateful for life, nature and community. When we feel part of the web of life, we can find the capacity to nurture it.